Heritage Project Celebrates Five Years of Harvesting the Best Images from Hubble Space Telescope

October 2, 2003: The Hubble Heritage team of astronomers, who assemble many of the NASA
Hubble Space Telescope's most stunning pictures, is celebrating its
five-year anniversary with the release of the picturesque Sombrero
galaxy. One of the largest Hubble mosaics ever assembled, this magnificent
galaxy has an apparent diameter that is nearly one-fifth the diameter of the full moon. The team used Hubble's Advanced Camera for Surveys to
take six pictures of the galaxy and then stitched them together to
create the final composite image. The photo reveals a swarm of stars
in a pancake-shaped disk as well as a glowing central halo of stars.

Q & A: Understanding the Discovery

1.
What gives the Sombrero its appearance?

The Sombrero, named because it resembles a broad-brimmed Mexican hat, is
oriented nearly edge-on to us. This edge-on view reveals that the disks
of spiral galaxies are incredibly thin. The disk displays dark dust
lanes, where many young and bright stars reside. The Hubble telescope
also shows that the glowing central bulge of stars harbors nearly 2,000
globular clusters of stars, 10 times as many as orbit our Milky Way galaxy.

2.
What is the Hubble Heritage Project?

The Hubble Heritage Project team, made up of astronomers and image
processing specialists from the Space Telescope Science Institute,
has been releasing an image from the Hubble Space Telescope every
month since 1998. Monthly image candidate come from previously
unreleased data from the Hubble telescope's photo archive
as well as new observations, like those of the Sombrero galaxy,
that are taken by the Heritage team for outreach purposes.

3.
What does angular diameter or apparent size mean?

The angular diameter (or the apparent size) of an object is an
expression of how wide an object appears to be. The moon is a fixed
distance from us and has a fixed inherent size (diameter). The Sombrero
galaxy is also of a fixed size and distance. Thus, we can compare their
apparent sizes. By saying that the Sombrero galaxy is one-fifth of the
diameter of the full moon, that means that if you were able to see the
Sombrero galaxy with the naked eye, you could take 5 of them and line
them up end to end, and what you see in the sky from these 5 galaxies
all lined up equals the same length as the diameter of the full moon.